JPH05129476A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a semiconductor device which can prevent the malfunction of its semiconductor element even when the element is subject to electromagnetic waves. CONSTITUTION:By mixing an electromagnetic wave absorbing agent 7, such as silicon carbide, whiskers, etc., which absorb electromagnetic noise in a resin 9 used for sealing a semiconductor element 3, external and internal noise to a semiconductor device 1 are prevented so that the malfunction of the element 3 can be eliminated and, at the same time, adverse influences on human bodies can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and its manufacturing method.

[0002]

2. Description of the Related Art In recent years, semiconductor packages have been made smaller and thinner in opposition to higher integration and larger scale of electronic circuit elements, and accordingly, circuits of electronic devices have been made higher in density. Therefore, electromagnetic waves from outside interfere with the operation of circuits, electromagnetic noise generated by the operation of electronic circuits interferes with the operation of other circuits, and further affects the human body. Therefore, measures against electromagnetic waves are indispensable for such electronic devices.

For example, a conventional resin-sealed semiconductor device 11
As shown in FIG. 9, a semiconductor chip 3 mounted on the die pad 2 and a lead frame 4 for electrically connecting the circuit wiring on the printed circuit board are connected by a metal wire 5, and these are connected. It is configured by sealing with resin 6, and as shown in FIG.
As shown in FIG. 0, with respect to the resin-sealed semiconductor device 11 connected on the printed board 17, the entire electronic device is covered with a shield material (electromagnetic wave shielding material) 18 to shield electromagnetic waves.

[0004]

However, in conventional electromagnetic wave countermeasures such as covering the entire electronic device with a shield material, adjacent semiconductor devices are mutually affected by the electromagnetic wave, so that malfunction of the electronic circuit is sufficiently prevented. There was a problem that I could not. An object of the present invention is to provide a semiconductor device and a manufacturing method thereof, which solve the above-mentioned conventional problems and prevent the influence of electromagnetic waves from the outside, and also prevent the influence of mutual electromagnetic waves between adjacent semiconductor devices. is there.

[0005]

In order to solve the above problems, the present invention adopts the following configuration. In the semiconductor device according to the invention of claim 1, an electromagnetic wave absorber that absorbs electromagnetic noise is mixed in the sealing material or the coating material of the semiconductor element. In the semiconductor manufacturing method of the invention of claim 2, after sealing the semiconductor device set in a small mold, the sealed semiconductor device is set in a large mold and an electromagnetic wave absorbent is mixed. Is used to reseal.

[0006]

According to the structure of the first aspect of the present invention, since the material that absorbs electromagnetic waves is mixed in the sealing material or the coating material, electromagnetic wave noise from the outside is absorbed and the internal circuit is not affected. Further, since electromagnetic wave noise from the inside of the semiconductor element is also absorbed and does not leak outside, malfunction of other electronic circuits can be prevented.

According to the second aspect of the present invention, since the conductive electromagnetic wave absorbent is manufactured in a solid state so as not to come into contact with the semiconductor device, occurrence of leak defects is suppressed and electromagnetic waves are reliably shielded. be able to.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the configuration of a resin-sealed semiconductor device 1 according to the first embodiment. The main body of the device 1 is configured as the same resin-sealed type as the conventional example shown in FIG. The same reference numerals indicate the same things. That is, in FIG. 1, 2 is a die pad, 3 is a semiconductor element, 4 is a lead frame, 5 is a metal wire, and 6 is a sealing resin.

The device of the embodiment shown in FIG. 1 differs from the conventional device in that a resin 9 containing an electromagnetic wave absorber 7 is vertically joined to a sealing resin 6 for sealing a semiconductor element 3 and molded. That is the point. This makes it possible to absorb electromagnetic waves from the outside and the inside of the semiconductor device, prevent malfunction of the electronic circuit, and prevent effects on the human body.
Silicon carbide, zinc oxide whiskers, etc. are used as the electromagnetic wave absorber 7.

As in FIG. 1, FIG. 2 is a cross-sectional view showing the structure of a ceramic-sealed semiconductor device in which a resin 9 mixed with an electromagnetic wave absorbent 7 is bonded and molded on the upper portion, and is constructed in this manner. However, the same effect can be obtained. FIG. 3 is a cross-sectional view showing the structure of the resin-sealed semiconductor device of the second embodiment, and the structure of the device body is the same as that of the first embodiment shown in FIG. The difference from the configuration of FIG. 1 is that the sealing resin 6 is mixed with an electromagnetic wave absorber 7 whose entire surface is coated with an insulating material 8 such as resin or rubber having a melting point higher than that of the sealing resin. This is a point formed by the sealing resin 6.

With such a structure, since the electromagnetic wave absorber 7 such as silicon carbide or zinc oxide whiskers has conductivity, between the metal wires 5, between the pins of the lead frame 4, or between the wirings on the printed circuit board. This is because if the electromagnetic wave absorber 7 is present over the area, there is a high possibility that a leak failure will occur during circuit operation. Therefore, the electromagnetic wave absorber is coated with the above-mentioned insulating material 8 in advance so that the electromagnetic wave absorber 7 does not come into contact with others. As a result, it is possible to suppress the occurrence of defective leakage.

In the second embodiment, as shown in FIG. 4, a resin 9 mixed with a coated electromagnetic wave absorber 7 may be bonded as a coating resin for the semiconductor element 3, and as shown in FIG. Similar effects can be obtained by coating the entire printed circuit board 11 on which the resin-sealed semiconductor device 10 is mounted, as potting resin, or as shown in FIG.

FIG. 7 shows a resin-encapsulated semiconductor device in which the entire device is assembled with a resin 9 mixed with an electromagnetic wave absorber 7 coated with an insulating material 8 such as resin or rubber having a melting point higher than that of the encapsulating resin. It is a figure showing the case where it is further sealed and configured as a resin double-sealed semiconductor device. With such a configuration, a more reliable electromagnetic wave shielding effect can be obtained.
8A and 8B are diagrams showing steps for carrying out the method for manufacturing the resin double-sealed semiconductor device shown in FIG. 7, in which the semiconductor device is manufactured by using sealing molds of different sizes. It is designed to be sealed.

First, as shown in FIG. 8A, the sealing resin 6 formed into a tablet by closing the die is pushed into the semiconductor device set in the small die 12 by the plunger 13, and the sealing resin 6 Is filled in the cavity and molded. Next, as shown in FIG. 8B, the semiconductor device 10 sealed with the sealing resin 6 is set in the large mold 14, and the electromagnetic wave absorber 7 whose surface is coated with a resin or the like is mixed into the tablet. The resin 9 thus converted is pushed by the plunger 15 to fill the cavity with the resin 9 for molding. Through such steps, the resin double-sealed semiconductor device can be easily manufactured.

[0015]

As described above, according to the semiconductor device of the present invention, since the electromagnetic wave absorbing material is mixed in the sealing material or the coating material, the electromagnetic wave noise from the outside is absorbed to the internal circuit. Since it has no influence and also absorbs electromagnetic noise from the inside of the semiconductor element and does not leak to the outside, it is possible to prevent malfunction of the electronic circuit formed by the semiconductor device and to greatly affect the human body. It has become possible to reduce.

Further, according to the semiconductor manufacturing method of the present invention, it is possible to easily manufacture a resin double-sealed semiconductor device and to provide a semiconductor device which can obtain a more reliable electromagnetic wave shielding effect. I can do it.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of a resin-sealed semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a configuration of a ceramic-sealed semiconductor device according to a first embodiment.

FIG. 3 is a sectional view showing a configuration of a resin-sealed semiconductor device according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing a configuration of a modified example of the second embodiment.

FIG. 5 is a sectional view showing a configuration of a modified example of the second embodiment.

FIG. 6 is a cross-sectional view showing a configuration of a modified example of the second embodiment.

FIG. 7 shows a cross-sectional view of a semiconductor device in which a resin according to a second embodiment of the present invention is sealed by a double sealing method.

FIG. 8 is a diagram illustrating a step of the manufacturing method of the present invention.

FIG. 9 is a cross-sectional view showing a configuration of a conventional resin-encapsulated semiconductor device.

FIG. 10 is a diagram illustrating a conventional electromagnetic wave countermeasure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor device 2 Die pad 3 Semiconductor element 4 Lead frame 5 Metal wire 6 Sealing resin 7 Electromagnetic wave absorber 8 Insulating material 9 Resin mixed with electromagnetic wave absorber 12 Small mold 14 Large mold

Claims (3)

[Claims] 1. A semiconductor device, wherein an electromagnetic wave absorber that absorbs electromagnetic wave noise is mixed in a sealing material or a coating material of a semiconductor element. 2. The semiconductor device according to claim 1, wherein the surface of the electromagnetic wave absorber is coated with an insulating material having a melting point higher than that of the sealing material or coating material for the semiconductor element. 3. A semiconductor device set in a small mold is sealed, then this sealed semiconductor device is set in a large mold, and sealed again using a sealing material mixed with an electromagnetic wave absorber. A method of manufacturing a semiconductor device, comprising: